Prior to this commit, `@ExceptionHandler` annotated controller methods
could be mapped using the exception type declaration as an annotation
attribute, or as a method parameter.
While such methods support a wide variety of method arguments and return
types, it was not possible to declare the same exception type on
different methods (in the same controller/controller advice).
This commit adds a new `produces` attribute on `@ExceptionHandler`; with
that, applications can vary the HTTP response depending on the exception
type and the requested content-type by the client:
```
@ExceptionHandler(produces = "application/json")
public ResponseEntity<ErrorMessage> handleJson(IllegalArgumentException exc) {
return ResponseEntity.badRequest().body(new ErrorMessage(exc.getMessage(), 42));
}
@ExceptionHandler(produces = "text/html")
public String handle(IllegalArgumentException exc, Model model) {
model.addAttribute("error", new ErrorMessage(exc.getMessage(), 42));
return "errorView";
}
```
This commit implements support in both Spring MVC and Spring WebFlux.
Closes gh-31936